Terrible for an HTPC solution as this method forces you to run media player home cinema in full screen mode with no on screen anything... no menus, buttons, controls whatever. This method has been around for a while, but you don't hear much about it because it's so unwieldy.
Not to mention, you're watching a movie, you don't really need your other cores. I have a Core 2 Duo 8550 and the highest it's ever peaked while decoding a 1080p movie was 64% and that's with crappy ffdshow. CoreAVC would probably fare even better.
In a perfect world, manufacturer's would be supporting native x264 decoding and they're not, because there's no money in an open source solution. Hopefully if enough people demand it, they'll start considering it...
